Method for measuring GPS air sensitivity and mobile terminal having function of measuring GPS air sensitivity

ABSTRACT

A mobile terminal having a function of measuring air sensitivity of global positioning system GPS and a method for measuring air sensitivity of GPS is disclosed. The mobile terminal includes: a memory for storing values of AGC PDM obtained by rotating a mobile terminal to a predetermined angle in a predetermined time period and obtaining values of AGC PDM in each predetermined angle; a computation unit for obtaining a mean value of values of AGC PDM; and a display unit for displaying the mean value.

FIELD OF THE INVENTION

The present invention relates to a mobile terminal having a function ofmeasuring air sensitivity of global positioning system GPS anddisplaying the measured air sensitivity of GPS on a display unit in amobile terminal.

DESCRIPTION OF RELATED ARTS

FIG. 1 is a flow chart showing a conventional method for measuring airsensitivity of global positioning system GPS. In the conventionalmethod, a user carries a mobile terminal having global positioningsystem GPS and enters a street or a field for a field test to measureair sensitivity of GPS in the mobile terminal at step S101. The userstarts to perform functions of GPS in the mobile terminal at step S102.The user determines whether or not the functions of the GPS in themobile terminal is well-performed by using additional equipment such asa diagnostic monitoring device and if the functions of the GPS iswell-performed, the user stops to measure the air sensitivity of the GPSat step S103. If the functions of the GPS are not well-performed, theuser performs a debugging procedure at step S104 and restart to wholeprocedure for measuring the air sensitivity of the GPS in the mobileterminal from the step S101.

The conventional method for measuring the air sensitivity of the GPS mayhave an advantage such that the user can measure air sensitivity of theGPS by himself. However, it also has drawbacks. At first, there is nonumerical reference for measuring the air sensitivity of GPS. Therefore,the air sensitivity of GPS cannot be accurately reported to users.According to the conventional method, the air sensitivity of GPS isanalyzed by user's experience of using the GPS. That is, the airsensitivity of GPS is tested and measured by performing the function ofGPS and determining how well the functions of GPS are performed.Secondly, after debugging the GPS in the mobile terminal, whole annoyingprocedure of measuring method is performed again such as the user has tocarry the mobile terminal having GPS functions and brings it outside forfield test.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a mobileterminal having a function to measure an air sensitivity of globalpositioning system GPS by obtaining a pulse density modulation valuefrom an auto gain control AGC amplifier in the mobile terminal, withoutusing additional equipment such as a diagnostic monitor.

It is another object of the present invention to provide a mobileterminal having a function to measure an air sensitivity of globalpositioning system GPS and displaying the measured air sensitivity on adisplay unit in the mobile terminal.

It is still another object of the present invention to provide a methodfor measuring air sensitivity of global positioning system GPS bypredicting the air sensitivity of GPS according to the pulse densitymodulation values from an auto gain control AGC amplifier in the mobileterminal and displaying the measured air sensitivity of GPS on a displayunit in the mobile terminal, without using additional equipment such asa diagnostic monitor.

In accordance with an aspect of the present invention, there is provideda method for measuring air sensitivity of global positioning system GPS,the method including the steps of: a) obtaining values of pulse densitymodulation PDM of auto gain control AGC amplifier in the mobile terminalwithin a predetermined time interval and storing the obtained values; b)analyzing the air sensitivity of the GPS by calculating a mean value ofobtained values; c) displaying an analyzing result of step b) on adisplay unit of the mobile terminal as the air sensitivity of GPS.

In accordance with an aspect of the present invention, there is alsoprovided a mobile terminal having a function to measure air sensitivityof global positioning system GPS, including: measurement mean forobtaining values of pulse density modulation PDM of auto gain controlAGC amplifier in the mobile terminal within a predetermined timeinterval; storage means for storing the obtained values; analysis meansfor analyzing the air sensitivity of the GPS by calculating a mean valueof obtained values; and display means for displaying the analyzingresult of the analysis means as the air sensitivity of the GPS.

BRIEF DESCRIPTION OF THE DRAWING(S)

The above and other objects and features of the present invention willbecome apparent from the following description of the preferredembodiments given in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a flow chart showing a conventional method for measuring airsensitivity of global positioning system GPS;

FIG. 2 is a flow chart of a method for measuring an air sensitivity ofglobal positioning system GPS in a mobile terminal in accordance of apreferred embodiment of the present invention;

FIG. 3 is a circuit diagram for illustrating a circuitry of mobileterminal measuring air sensitivity of GPS in accordance with a preferredembodiment of the present invention;

FIG. 4 is a perspective view showing a method for measuring referenceair sensitivity of GPS in a radio anechoic chamber in accordance with apreferred embodiment of the present invention; and

FIG. 5 is a flow chart showing a method for measuring air sensitivity ofGPS in accordance with a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Other objects and aspects of the invention will become apparent from thefollowing description of the embodiments with reference to theaccompanying drawings, which is set forth hereinafter.

FIG. 2 is a flow chart of a method for measuring an air sensitivity ofglobal positioning system GPS in a mobile terminal in accordance of apreferred embodiment of the present invention.

Referring to FIG. 2, a method for measuring air sensitivity of globalpositioning system in a mobile terminal is explained hereinafter.

At first, a user starts to operate a mobile terminal to measure airsensitivity by selecting a GPS mode at step S201. The mobile terminalobtains pulse density modulation PDM values of auto gain control AGCamplifier in the mobile terminal within a predetermined time intervaland the obtained PDM values are stored at step S202. The PDM values arevaried corresponding to strength of GPS signal and it is used formeasuring air sensitivity of GPS in the present invention. After storingPDM values, a mean value of obtained PDM values is computed at stepS203. After computing the mean value, the mean value is displayed on adisplay unit as the air sensitivity of GPS at step S204. The mean valuecan be displayed as a various form such as a number, a graph or asymbolic diagram.

FIG. 3 is a circuit diagram for illustrating a circuitry of mobileterminal measuring air sensitivity of GPS in accordance with a preferredembodiment of the present invention.

Referring to FIG. 3, the circuit includes a plurality of auto gaincontrol AGC amplifier 311 and 312, a switch 320, a voltage controloscillator 330, a divider 340, a plurality of mixer 351 and 352, aplurality of low pass filers LPS 361 to 364, a plurality of amplifiers371 and 372, a plurality of analog to digital converters ADC 381 and382, a controller 390 (e.g., mobile station modem MSM available fromQualcomm Incorporated.) and a RC LPF 391.

A plurality of AGC amplifiers 311 and 312 receives input signal of CDMAIF or input signal of GPS IF, amplifies the input signal of CDMA IF orthe input signal of GPS IF. It also dynamically controls its gainsaccording to pulse density modulation PDM signal from the MSM 390.

Hereinafter, operations of the AGC amplifiers 311 and 312 are explainedin detail.

The AGC amplifiers 311 and 312 control gain to maintain predeterminedstrength level of signals inputted to the ADC 381 and 382. That is, amobile station modem MSM 390 measures strength level of input signals tothe ADCs 381 and 382 before inputting to the ADCs 381 and 382 andobtains PDM values according to measured strength level of inputsignals. After obtaining the PDM value, it is transmitted to a RC LPF391 for transforming to DC value. The DC value is feedback to AGCamplifiers 311 and 312 through the AGC control pine. Finally, the AGCamplifiers 311 and 312 receive the DC value and control gain to maintainpredetermined strength level of input signals to the ADCs 381 and 382based on the DC value. For example, if weak input signals are inputtedto ADC 381 and 382, the AGC amplifiers controls to have high gain and ifstrong input signals are inputted to ADC 381 and 382, the AGC amplifierscontrol to have low gain to maintain predetermined strength level ofinput signals to the ADCs 381 and 382.

Therefore, according to the PDM signal from the MSM, gain of the AGCamplifiers 311 and 312 is varied and it is used as measuring the airsensitivity of GPS.

The switch 320 alternatively passes one of output signals of a pluralityof AGC 311 and 312 according to CDMA mode or GPS mode.

The VCO 330 generates local frequency signal and outputs the localfrequency signal to the divider 340.

The divider 340 divides the local frequency signal to a plurality ofdivided frequency signals and outputs a plurality of divided frequencysignals to a plurality of mixers 351 and 352.

A plurality of mixers 351 and 352 generates a mixed signal by mixingoutput signals of the switch 320 and divided signals from the divider340 and outputs the mixed signal to the a plurality of LPF 361 to 364.

A plurality of LPF 361 to 364 receives the mixed signal from the mixers351 and 352 and generates a filtered signal by filtering the mixedsignal according to the CDMA mode or GPS mode.

A plurality of amplifiers 371 and 372 receives the filtered signal fromthe LPF 361 to 364 and generates amplified signals by amplifying thefiltered signal. The amplified signals are outputted to a plurality ofADC 381 and 382.

A plurality of ADC 381 and 382 receives the amplified signal and covertsthe amplified signal to In-phase signal and Quadrature-phase signal as adigital signal.

As mentioned above, the PDM values varied corresponding to strength ofinput signals to the ADC are stored in a memory(not shown) and its meanvalue is obtained by a process unit (not shown). The mean value isdisplayed for showing air sensitivity of GPS on the display unit of themobile terminal.

The present invention can be used for determining a reference value ofair sensitivity of GPS.

FIG. 4 is a perspective view showing a method for measuring airsensitivity of GPS in a radio anechoic chamber in order to determine airsensitivity reference of GPS in accordance with a preferred embodimentof the present invention.

Referring to FIG. 4, an antenna is installed to a global positioningsystem GPS signal generator for radiating GPS signal in the radioanechoic chamber. After installing the antenna, a mobile terminal 14 isposted around of the antenna. The mobile terminal 14 is automaticallyrotated to 15 degree in every a predetermined time period by using amotor (not shown). Every time the mobile terminal 14 is rotated in apredetermined degree, pulse density modulation PDM values are obtainedand stored in the mobile terminal 14. The PDM values are variedaccording to strength of GPS signal. The PDM values are measured andstored in the mobile terminal until the mobile terminal is rotated to360 degree. The PDM values of IF-baseband Chipset are stored and a meanvalue of the AGC PDM values is computed. The mean value is determined asa reference value and it can be used for analyzing the air sensitivityof the GPS in the mobile terminal in any occasions. Therefore, based onthe air sensitivity reference measured in the radio anechoic chamber 10,the air sensitivity of the GPS can be accurately measured in anycircumstances. Such a measured air sensitivity can be displayed througha LCD displayer in the mobile terminal.

FIG. 5 is a flow chart showing a method for measuring air sensitivity ofGPS in order to determine air sensitivity reference of GPS in accordancewith a preferred embodiment of the present invention.

Referring to FIG. 5, at first, a user starts to operate a mobileterminal to measure air sensitivity by selecting a GPS mode at stepS501. The user puts the mobile terminal in a radio anechoic chamber, inwhich an antenna transmitting signal of base station is installed androtates the mobile terminal in a predetermined angle at step S502. Inthe preferred embodiment of the present invention, the mobile terminalis rotated in 15 degree.

The mobile terminal obtains AGC PDM values which are variedcorresponding to amplitude of GPS signal and the obtained AGC PDM valuesare stored at step S503.

After completing to rotate the mobile terminal to 360 degree, a meanvalue of obtained AGC PDM values is computed at step S504. Aftercomputing the mean value, the mean value is set as a reference value andair sensitivity of GPS at step S505.

As mentioned above, the present invention uses a pulse densitymodulation value of AGC amplifier in the mobile terminal to measuringair sensitivity of GPS. Therefore, the present invention can predict anair sensitivity of GPS without using additional diagnostic equipmentsuch as a diagnostic monitor DM. Also, the measured air sensitivity ofGPS can be displayed at a LCD displayer on the mobile terminal andtherefore, the user can conveniently monitor the air sensitivity of theGPS.

While the present invention has been described with respect to certainpreferred embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the scope of the invention as defined in the following claims.

1. A method for measuring an air sensitivity of a global positioningsystem (GPS) in a mobile terminal, the method comprising the steps of:obtaining a GPS signal value in the mobile terminal, and displaying theair sensitivity of the GPS on a display unit of the mobile terminalusing the GPS signal value.
 2. The method as recited in claim 1, furthercomprising the steps of: comparing the GPS signal value to a referenceGPS signal value previously stored in a memory of the mobile terminal;and displaying the air sensitivity of the GPS using the comparisonresult on the display unit.
 3. A method for measuring an air sensitivityof a global positioning system (GPS) in a mobile terminal, the methodcomprising the steps of: detecting a GPS signal in the mobile terminal;analyzing the GPS signal; and displaying the air sensitivity of the GPSon a display unit of the mobile terminal by using the analyzing result.4. A method for measuring an air sensitivity of a global positioningsystem (GPS) in a mobile terminal, the method comprising the steps of:detecting a GPS baseband signal in the mobile terminal; analyzing theGPS baseband signal; and displaying the air sensitivity of the GPS on adisplay unit of the mobile terminal by using the analyzing result.
 5. Amobile terminal, comprising: a controller for obtaining a GPS signalvalue; and a display unit for displaying an air sensitivity of the GPSby using the GPS signal value.
 6. The mobile terminal of claim 5,further comprising, a memory for storing a reference GPS signal value,wherein the controller compares the GPS signal value to the referenceGPS signal value, and the display unit displays the air sensitivity ofthe GPS using the comparison result.
 7. A mobile terminal, comprising: acontroller for detecting a GPS signal in the mobile terminal andanalyzing the GPS signal; and a display unit for displaying a GPS airsensitivity by using the analyzing result.
 8. A mobile terminal,comprising: a controller for detecting a GPS baseband signal in themobile terminal and analyzing the GPS baseband signal; and a displayunit for displaying a GPS air sensitivity by using the analyzing result.